Aplicabilidade das estratégias para prevenção e diagnóstico precoce do câncer de boca: uma revisão guarda-chuva / Applicability of strategies for prevention and early diagnosis of oral cancer: an umbrella review

O câncer de boca é o sexto câncer mais comum em todo o mundo e representa um problema global crescente. Apesar disso, 70% desses cânceres são diagnosticados em estágios avançados, reforçando a importância de estratégias para prevenção e detecção precoce do câncer. Este trabalho tem como objetivo investigar a aplicabilidade de estratégias para detecção precoce do câncer de boca. Como existem diversas revisões sistemáticas já publicadas sobre o tema, a proposta é realizar uma revisão guarda-chuva das revisões sistemáticas. As buscas realizadas nas bases de dados resultaram em 2145 artigos, e outras fontes de informações acrescentaram mais 114 artigos. Após a detecção de artigos duplicados eletrônica e manualmente, em conjunto com a primeira fase da revisão, 83 artigos foram selecionados para a segunda fase da revisão. Por fim, 46 revisões sistemáticas foram incluídas neste estudo, tendo 9 artigos sido considerados confiáveis para sumarização da evidência atual. Artigos cuja estratégia foi de exame clínico convencional realizado por profissionais treinados e estudos em que houve um maior acesso dos indivíduos à saúde bucal, apresentaram um resultado mais preciso, confiável e custo-efetivo na avaliação dos grupos de indivíduos de alto risco. Em geral, os métodos auxiliares que apresentaram resultados promissores foram aqueles à base de autofluorescência e citopatologia. As estratégias de rastreamento não devem ser descartadas, uma vez que ainda há uma carência de estudos de alta qualidade nesse tema.

Identification of mutations in canine oral mucosal melanomas by exome sequencing and comparison with human melanomas.

Oral mucosal melanomas (OMMs) are aggressive neoplasms commonly found in dogs but rare in humans. Utilizing whole exome sequencing (WES), which focuses on protein-coding regions to reveal mutation profiles, we conducted a comparative analysis of canine OMM and human melanomas. This study involved DNA extraction, exome enrichment, and sequencing from three canine OMM cell lines (CMGD-2, CMGD-5, TLM-1), five canine OMM frozen samples, a human OMM cell line (MEMO), and a human commercial skin melanoma cell line (SK-MEL-28). The sequencing and subsequent analysis of FASTQ files yielded final variant files, leading to the identification of mutations. Our findings revealed a total of 500 mutated genes in canine OMM, including significant ones such as EP300, FAT4, JAK3, LRP1B, NCOR1, and NOTCH1. Notably, 82 shared mutations were identified between human melanomas and canine OMM genomes. These mutations were categorized based on the gene functions. The identification of these mutations provides critical insights that can pave the way for the development of novel therapeutic strategies for both canine and human OMM, offering hope for more effective treatments in the future.

Antitumoral and Antiproliferative Potential of Synthetic Derivatives of Scorpion Peptide IsCT1 in an Oral Cavity Squamous Carcinoma Model.

The oral cavity is a frequent site for head and neck cancers, which rank as the sixth most common cancer globally, with a 5-year survival rate slightly over 50%. Current treatments are limited, and resistance to therapy remains a significant clinical obstacle. IsCT1, a membrane-active peptide derived from the venom of the scorpion Opisthacanthus madagascariensis, has shown antitumor effects in various cancer cell lines, including breast cancer and chronic myeloid leukemia. However, its hemolytic action limits its potential therapeutic use. This study aims to assess the antitumor and antiproliferative activities of synthetic peptides derived from IsCT1 (IsCT-P, AC-AFPK-IsCT1, AFPK-IsCT1, AC-KKK-IsCT1, and KKK-IsCT1) in the context of oral squamous cell carcinoma. We evaluated the cytotoxic effects of these peptides on tongue squamous cell carcinoma cells and normal cells, as well as their impact on cell cycle phases, the expression of proliferation markers, modulators of cell death pathways, and mitochondrial potential. Our results indicate that the IsCT1 derivatives IsCT-P and AC-AFPK-IsCT1 possess cytotoxic properties towards squamous cell carcinoma cells, reducing mitochondrial membrane potential and the proliferative index. The treatment of cancer cells with AC-AFPK-IsCT1 led to a positive modulation of pro-apoptotic markers p53 and caspases 3 and 8, a decrease in PCNA and Cyclin D1 expression, and cell cycle arrest in the S phase. Notably, contrary to the parental IsCT1 peptide, AC-AFPK-IsCT1 did not exhibit hemolytic activity or cytotoxicity towards normal cells. Therefore, AC-AFPK-IsCT1 might be a viable therapeutic option for head and neck cancer treatment.

Herpesviruses and human papillomaviruses in saliva and biopsies of patients with orofacial tumors.

OBJECTIVES: To determine the prevalence and association of HPV and Herpesviruses in saliva and tissue samples of patients with orofacial tumors. METHODS: Biopsies of tumors were done, and saliva samples were collected from patients with orofacial tumors for the determination of viruses using nested multiplex PCR. Independent variables were sex, age, comorbidities, tumor stage, and length of stay. Outcome variables were the presence or absence of herpesviruses and HPV. Descriptive summaries and inferential statistics were done. RESULTS: A hundred patients were included in the study. Prevalence of herpesviruses and HPV were 17.6 % and 57.0 % in tumors, and 48.3 % and 60.0 % in the saliva of patients respectively. Herpesviruses detected included EBV (21.3 %), HHV-7 (11.2 %), CMV (6.7 %), HSV-1 (5.1 %), HSV-2 (1.1 %), VZV (1.1 %), and Kaposi sarcoma virus (0.6 %). The most prevalent HPV genotypes were HPV-42 (29 %), HPV-43 (22.7 %), HPV-52 (22.2 %), HPV-39 (18.8 %), and HPV-18 (9.1 %). The odds of EBV being detected in malignant orofacial tumors were 2 times that of benign orofacial tumors. HPV DNA in the saliva of patients with orofacial tumors was 69.7 %, compared to 18.2 % of the control sample (p < 0.001). The median length of stay for all participants was 6.5 days, those associated with viruses stayed longer. CONCLUSION: There was a high prevalence of Herpesviruses and HPV in saliva and tumor samples of patients with orofacial tumors, signalling some potential for more work to be done in this area.

Salivary biomarkers in non-invasive oral cancer diagnostics: a comprehensive review.

OBJECTIVE: This review aims to provide a comprehensive analysis of the effectiveness of saliva as a non-invasive diagnostic marker for oral cancer. Despite progress in oral cancer diagnosis and prognosis, the 5-year survival rate remains low due to the resistance to treatment and delayed diagnosis, which can be attributed to various factors including tobacco and alcohol consumption, genetic damage, and human papillomavirus (HPV). The potential use of saliva as an easily accessible non-invasive screening and diagnostic method arises from its direct contact with the lesion site. METHODOLOGY: Data for this study were gathered via a comprehensive literature evaluation using search engines such as the PubMed, Web of Science, Google Scholar, and SciFinder. RESULTS: Identifying salivary biomarkers shows potential to transform oral cancer diagnostics by offering a reliable alternative to the traditional invasive methods. Saliva is an abundant reservoir for both cell-bound and cell-free organic and inorganic constituents. Thus, saliva is an appropriate field for research in proteomics, genomics, metagenomics, and metabolomics. CONCLUSION: This review provides a comprehensive elucidation of salivary biomarkers and their function in non-invasive oral cancer diagnosis, demonstrating their potential to enhance patient outcomes and reduce the impact of this devastating disease.

Diet and Oral Squamous Cell Carcinoma: A Scoping Review.

Oral squamous cell carcinoma (OSCC) is the sixth most common type of cancer globally. While smoking is a key risk factor, rising cases in non-smokers highlight the need to explore other factors like diet. This scoping review aims to deepen the evidence on the relationship between OSCC and diet, following PRISMA-ScR guidelines, and was registered on Open Science Framework. Searches were performed in four electronic databases: MEDLINE, Embase, Web of Science, and Lilacs, without date or language restrictions. Studies were evaluated, extracted, and compiled in a narrative table. Seventeen studies with 10,954 patients were analyzed. Most patients were male (74.63%), aged 18-89 (average 50.62). Studies were mainly from high (82%) and medium (17%) Human Development Index (HDI) countries. Dietary surveys included a Food Frequency Questionnaire (FFQ) (58.8%), interviews/questionnaires (17.6%), and an FFQ with a photographic atlas (5.9%). Certain foods in excess like fruits, vegetables, and tea were inversely associated with OSCC, while salty meats, dairy, coffee, sausages, and fried and spicy foods were positively associated. Due to the heterogeneity of the tools used to obtain food frequency data, the results should be interpreted cautiously. New standardized studies and randomized trials are essential to advance understanding and control confounding factors in this field.

Estimating the burden of care for oral potentially malignant disorders and oral cancer in Brazilian dental practice.

BACKGROUND: Oral cancer (OC) and oral potentially malignant disorders (OPMD) pose significant challenges to public health in Brazil. This study aimed to estimate the prevalence of oral cancer (OC) and oral potentially malignant disorders (OPMD) among patients who would be treated by Brazilian dentists during their careers. MATERIAL AND METHODS: Data on the number of dentists in Brazil were extracted from the 2022 census data, while incidence rates for OC cases were sourced from the Brazilian National Cancer Institute (INCA). Population estimates for Brazil and data on dental check-up rates were obtained from relevant national sources. RESULTS: Our analysis indicates that a general dentist in Brazil can expect to encounter on average two to three OC patients and on average 675 patients with OPMDs over a 35-year career. Regional disparities were observed, with certain regions showing higher than the average number of encounters due to low density of dentists in some rural districts. CONCLUSIONS: Brazilian dentists are likely to confront a substantial number of OC and OPMD cases during their professional tenure, emphasizing the need for public health policies aimed at enhancing dental surgeons' education in oral cancer prevention and early detection.

Analysis of scientific publications on oral cancer diagnosis delays: a bibliometric study over 22 years.

BACKGROUND: The area of oncology still lacks bibliometric studies that investigate the diagnostic interval of oral cancer. This study proposed to carry out a bibliometric analysis of epidemiological studies that investigated the diagnosis of oral cancer between 2002 to 2024. MATERIAL AND METHODS: On April, 2024, the Scopus and Web of Science databases were explored, and the selected articles underwent bibliometric analysis of performance and scientific mapping of journals, authors, institutions, and countries, as well as the predominant topics and trends in research into the diagnosis of oral cancer through an analysis of references and co-occurrence of key words. The analyzes were carried out using the R extension package, Bibliometrix, and the VOSviewer software. RESULTS: A total of 532 documents were included. China contributed the highest number of publications (36.71%) and total citations [1,584]. Seoane J was the most prolific author [16 (h-index: 9)], while Warnakulasuriya S had the highest total link strength [282 (h-index: 7)] in co-citations. Oral Oncology was identified as the most prolific [231 (72.64%)], co-cited and impactful journal (h-index: 13). Explosions of citations were found for keywords such as "early diagnosis", "biomarker", "saliva", "precancer" and "prognosis", making it evident that in the field of oral cancer diagnosis there is room for new studies focusing in reducing the diagnostic interval, with the research hotspots being the terms "biomarkers", "imaging diagnosis" and "gene expression". CONCLUSIONS: This study provides valuable information that can help researchers and institutions align their research activities according to emerging themes, establish collaborations and allocate resources effectively.

Leukoplakia and erythroplakia in youngers versus older individuals: a clinicopathological retrospective study.

BACKGROUND: The incidence of oral cancer has exhibited a rise within the young population. Considering that oral potentially malignant disorders (OPMDs) can precede the development of oral cancer, it is imperative to conduct studies in this particular younger population. This study aimed to evaluate the frequency and conduct a comparative analysis of the clinical-demographic characteristics of OPMDs in two distinct age groups. MATERIAL AND METHODS: A retrospective analysis was conducted with patients diagnosed with leukoplakia, erythroplakia, and leukoerythroplakia between 1965 and 2020. The individuals were categorized into two groups: those aged up to 40 years (Group Younger) and those aged 41 years and above (Group Older). RESULTS: A total of 640 lesions were subjected to analysis. Among these, patients aged up to 40 years constituted 10.63% of the sample, however, this proportion decreased significantly to 6.9% between 2010 and 2020. A predominant male representation was observed in both groups, with white lesions being the most common in both as well. However, the frequency of red or mixed lesions was significantly higher (p=0.034) in the older group, along with a higher prevalence of dysplastic lesions (26.9% versus 11.8%, p=0.01). Moreover, the older group exhibited a relatively higher percentage of smokers/ex-smokers (78.6%), compared to the younger group (61.5%, p=0.085) and alcohol consumers/ex-consumers (54.9% versus 22.7%, p=0.028). Elderly individuals exhibited an unfavorable progression (p=0.028). However, a logistic regression analysis identified as significant variables associated with malignant transformation, the presence of epithelial dysplasia, and red lesions diagnosed as erythroplakia. CONCLUSIONS: A declining frequency of OPMDs in young adults was observed over the years, whereas in older adults, these disorders exhibited an unfavorable progression.

Chitosan-based mucoadhesive films loaded with curcumin for topical treatment of oral cancer.

This study aimed to develop mucoadhesive chitosan-based films capable of enhancing the curcumin penetration into the oral mucosa to treat oral cancers. We developed three films containing medium molecular weight chitosan (190-310 KDa) and other excipients (polyvinyl alcohol, Poloxamer®407, and propylene glycol) that have proven to be compatible with each other and with curcumin in thermal analyses. The films were smooth, flexible, and precipitates free, with uniform weight and thickness, pH compatible with the oral mucosa, resistance to traction, and entrapped curcumin in a high proportion. They also exhibited necessary swelling and mucoadhesion for tissue adherence. Ex vivo penetration studies proved that the films significantly increased the penetration of curcumin into the oral mucosa compared to control, even when the mucosa was subjected to a condition of simulated salivation. Curcumin exhibited cytotoxic activity in vitro in the two head and neck cancer cell lines (FaDu, SCC-9) at doses close to those found in penetration studies with the films. When combined with radiotherapy, curcumin demonstrated superiority over single doses of radiotherapy at 4, 8, and 12 Gy. Therefore, the developed films may represent a promising alternative for the topical treatment of oral tumors.

Effects of artemisinin and cisplatin on the malignant progression of oral leukoplakia. In vitro and in vivo study.

OBJECTIVES: Chemoprevention can be a treatment for potentially malignant lesions (PMLs). We aimed to evaluate whether artemisinin (ART) and cisplatin (CSP) are associated with apoptosis and immunogenic cell death (ICD) in vitro, using oral leukoplakia (OL) and oral squamous cell carcinoma (OSCC) cell lines, and whether these compounds prevent OL progression in vivo. METHODS: Normal keratinocytes (HaCat), Dysplastic oral cells (DOK), and oral squamous cell carcinoma (SCC-180) cell lines were treated with ART, CSP, and ART + CSP to analyze cytotoxicity, genotoxicity, cell migration, and increased expression of proteins related to apoptosis and ICD. Additionally, 41 mice were induced with OL using 4NQO, treated with ART and CSP, and their tongues were histologically analyzed. RESULTS: In vitro, CSP and CSP + ART showed dose-dependent cytotoxicity and reduced SCC-180 migration. No treatment was genotoxic, and none induced expression of proteins related to apoptosis and ICD; CSP considerably reduced High-mobility group box-1 (HMGB-1) protein expression in SCC-180. In vivo, there was a delay in OL progression with ART and CSP treatment; however, by the 16th week, only CSP prevented progression to OSCC. CONCLUSION: Expression of proteins related to ICD and apoptosis did not increase with treatments, and CSP was shown to reduce immunogenic pathways in SCC-180, while reducing cell migration. ART did not prevent the malignant progression of OL in vivo; CSP did despite significant adverse effects.

Oral T-cell-rich large B-cell lymphoma in a horse.

Lymphoma is the most common tumor of hematopoietic origin in horses. The course of the disease and clinical signs vary greatly, depending on tumor location and extent. The aim of this report is to describe the occurrence of T-cell-rich oral large B-cell lymphoma with marked local infiltration in a 25-year-old Crioula mare. The mare showed an increase in volume on the right side of its face, dyspnea, anorexia, and progressive weight loss. The clinical assessment showed that the lesion was located in the rostral and caudal sinuses and was markedly invasive to adjacent structures. The autopsy revealed a yellow mass with a soft to firm consistency, infiltrating multiple bones in the skull, and extensively invading the hard palate and masseter muscle. Histologically the mass comprised an undifferentiated malignant neoplasm characterized by a densely cellular neoplasm composed of large CD20 + neoplastic B-lymphocytes admixed with sheets of small, CD3 + reactive T-lymphocytes supported by delicate fibrovascular stroma leading to the diagnosis of oral T-cell-rich large B-cell lymphoma.

Metformin Radiosensitizing Effect on Hypoxic Oral Squamous Cell Carcinoma Cells by GAPDH and TAGLN2.

OBJECTIVE: Tumor hypoxia is associated with a poorer prognosis in cancer patients and can diminish the efficacy of radiation therapy (RT). This study investigates the potential of metformin to enhance radiosensitivity in hypoxic cancer cells. METHODS: Preliminary experiments were conducted to validate the impact of hypoxia on radiation response. Reactive oxygen species (ROS) levels, cell migration, and cell death were assessed in hypoxic, radiated cells treated with metformin. Proteomic and ontological analyses were employed to identify molecular targets associated with the radiosensitizing effect of metformin. Proteomic and ontological findings were validated through patient samples and in vitro studies. RESULTS: Metformin amplified cell death, induced DNA fragmentation, decreased cell migration, and elevated ROS levels in hypoxic, radiated cells. Proteomic analyses revealed that GAPDH and TAGLN2 were identified as pivotal targets linked to the radiosensitizing effect of metformin. Oral cancer patients exhibited elevated levels of TAGLN2 and reduced levels of GAPDH. Metformin downregulated TAGLN2 and upregulated GAPDH in hypoxic, radiated cells. Additionally, metformin reduced levels of mutated p53. CONCLUSIONS: This study suggests that metformin can enhance radiosensitivity in hypoxic cells, operating through modulation of GAPDH and TAGLN2. Furthermore, metformin effectively reduces mutated p53 levels in radiated cells under hypoxic conditions.

Salivary 8-hydroxy-2'-deoxyguanosine levels in patients with oral cancer: a systematic review and meta-analysis.

BACKGROUND: DNA is an important target for oxidative attack and its modification may increase the risk of mutagenesis. The aim of this study was to evaluate and compare salivary levels of the oxidative stress biomarker 8-hydroxy-2'-deoxyguanosine (8-OHdG) in patients with oral cancer (OC) compared to the control group by a comprehensive search of the available literature. METHODS: The present systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines and was registered in Open Science Framework (OSF): https://doi.org/10.17605/OSF.IO/X3YMR. Four electronic databases were used to identify studies for this systematic review: PubMed, Scopus, ScienceDirect, and Web of Science from January 15, 2005, to April 15, 2021. The Joanna Briggs Institute (JBI) tool was used to assess article quality. RESULTS: Of the 166 articles identified, 130 articles were excluded on the basis of title and abstract screening (duplicates, reviews, etc.). Thirty-six articles were evaluated at full text and 7 articles met the inclusion criteria. Of these, only 5 studies had compatible data for quantitative analysis. An increase in salivary 8-OHdG levels was found in patients with OC compared to healthy subjects, but without statistical significance. 8-OHdG: SMD = 2,72 (95%CI= -0.25-5.70); *p = 0.07. CONCLUSIONS: This systematic review and meta-analysis suggests a clear trend of increased 8-OHdG levels in saliva of OC patients compared to the control group. However, further studies are required to clarify and understand the altered levels of this oxidative stress marker.

Cáncer oral: etiología, lesiones precancerosas y tratamiento / Oral cancer: etiology, precancerous lesions and treatment

Introducción: el cáncer oral es una de las neoplasias malignas más comunes en el mundo, sin embargo, a pesar de las herramientas diagnósticas actuales, existe un alto grado de morbilidad y mortalidad debido al diagnóstico tardío y a la falta de conciencia por parte de la población sobre el consumo de tabaco, alcohol, entre otras sustancias. Objetivo: el objetivo de la presente revisión es brindar información actual sobre las lesiones precancerosas, etiología, diagnóstico y tratamiento del cáncer oral. Material y métodos: se realizó una búsqueda bibliográfica en cinco bases de datos digitales sobre artículos revisados por pares desde el 2015 hasta la actualidad. Conclusión: el cáncer oral es una patología frecuente que causa graves consecuencias y secuelas en las personas que lo padecen, un conocimiento amplio de las lesiones premalignas junto con el diagnóstico temprano por parte del profesional y una mayor conciencia sobre los factores de riesgo, juegan un papel fundamental para prevenir la presencia y desarrollo de esta patología (AU)

Introduction: oral cancer is one of the most common malignant neoplasms in the world, despite the current diagnostic tools, there is a high degree of morbidity and mortality due to late diagnosis and lack of awareness of the population on the consumption of tobacco, alcohol, among other substances. Objective: the objective of this review is to provide present information of the precancerous lesions, etiology, diagnosis and treatment of oral cancer. Material and methods: a bibliographic search was carried out in five digital databases on peerreviewed articles from 2015 to the present. Conclusion: oral cancer is a frequent pathology that can cause serious consequences and sequelae in people who suffer it, an extensive knowledge of premalignant lesions among with an early diagnosis by the professional and a greater awareness of risk factors, play a fundamental role to prevent the establishment and/or progression of this pathology (AU)

Carcinoma oral de células escamosas y su posible asociación con la higiene bucal / Oral squamous cell carcinoma and possible association with oral hygiene

El cáncer se caracteriza por la falta de diferenciación citológica, autonomía de la homeostasis local y general; el cáncer bucal ocupa el sexto sitio de frecuencia de todas las áreas del cuerpo. Alrededor de 90% de los tipos histológicos de cáncer en cavidad bucal corresponden a carcinoma bucal de células escamosas (COCE) (AU)

Cancer is characterized by a lack of cytological differentiation, autonomy of local and general homeostasis, and oral cancer ranks sixth frequency site of all areas of the body. About 90% of histologic types of oral cavity cancer are OSCC (AU)

Histiocytic sarcoma affecting the oral cavity: a clinical, pathologic and molecular study.

OBJECTIVE: To investigate the clinicopathological, immunohistochemical and molecular features of histiocytic sarcomas affecting the oral cavity. METHODS: Pathology files of two institutions were searched for cases of histiocytic sarcoma, and new H&E-stained slides and immunohistochemistry reactions evaluated for diagnosis confirmation. Molecular screening for KRAS and PIK3CA mutations was performed through polymerase chain reaction (PCR) followed by Sanger sequencing. BRAFp.V600E mutation was assessed by pyrosequencing. Clinical data regarding sex, age, tumor location, systemic manifestations, clinical presentation, follow-up time, treatment applied and status at last follow-up were collected from patients' pathology and medical files. RESULTS: Three cases were retrieved during the period investigated (2000-2023). Two females and one male were affected, with a wide age range, involving the tongue, palate and gingiva. Histopathologically, the neoplasms presented as highly pleomorphic atypical cells distributed diffusely with infiltration of normal structures. All cases demonstrated histiocytic differentiation expressing CD68 and CD163, and a high Ki67 expression. Genetic mutations were evaluated in two cases. One case harboured BRAF-V600E mutation, but not in KRAS and PIK3CA, while the second case did not show mutation in BRAF-V600E, KRAS and PI3KCA. One patient was lost, and two patients died after eight and four months of follow-up. CONCLUSION: Histiocytic sarcomas involving the oral cavity are extremely rare, and may represent dissemination of a systemic condition. It has an aggressive biological behaviour with a poor overall prognosis.

Atypical cellular neurothekeoma of the oral mucosa: A rare case report and literature review.

Cellular neurothekeoma (CN) is a benign dermal neoplasm that most often affects the head and neck region and rarely occurs in the oral mucosa. We report a rare case of CN with atypical features on the floor of the mouth and summarize the reported cases of oral CN in English-language literature. A 62-year-old woman presented with a 6-month history of a painless mass on the floor of the mouth. Histopathological analysis of the excised specimen revealed a proliferation of neoplastic cells with oval to spindle morphology arranged in a vaguely nested and multinodular architecture separated by scarce hyaline collagen within a predominantly myxoid-rich stroma. The tumor cells were positive for NSE, and CD63 (NKI/C3), and negative for S100 protein, CD34, and SMA. Thus, the final diagnosis was CN. In addition, we summarized all clinicopathological data on oral CNs reported in the English-language literature. Nineteen cases were reviewed. Among them, only one case affected the floor of the mouth of a young girl, in contrast to the present case that occurred in an elderly woman. CN is particularly rare in this location and may be a diagnostic challenge for oral pathologists due to its rarity and morphological similarity with other lesions.

5-ALA mediated photodynamic therapy increases natural killer cytotoxicity against oral squamous cell carcinoma cell lines.

Oral squamous cell carcinoma (OSCC) constitutes over 90% of oral cancers, known for its aggressiveness and poor prognosis. Photodynamic therapy (PDT) has emerged as a promising adjuvant therapy and is linked to immunogenic cell death, activating innate and adaptive anti-tumor responses. Natural Killer (NK) cells, key players in malignant cell elimination, have not been extensively studied in PDT. This study evaluates whether PDT increases OSCC cell lines' susceptibility to NK cell cytotoxicity. PDT, using 5-aminolevulinic acid (5-ALA) and LED irradiation, was applied to Ca1 and Luc4 cell lines. Results showed a dose-dependent viability decrease post-PDT. Gene expression analysis revealed upregulation of NK cell-activating ligands (ULBP1-4, MICA/B) and decreased MHC class I expression in Ca1, suggesting increased NK cell susceptibility. Enhanced NK cell cytotoxicity was confirmed in Ca1 but not in Luc4 cells. These findings indicate that PDT may enhance NK cell-mediated cytotoxicity in OSCC, offering potential for improved treatment strategies.